The present invention generally relates to modifications to projectiles where an expandable attachment member is joined to the base of the projectile body.
Prior art bullets used to create lethal wounds have undergone significant modifications to allow the projectile body to have a relatively small cross section with an aerodynamic shape for in-flight stability and increased accuracy over a longer range. Upon impact with the target, the projectile body deforms rapidly and increases in cross section, causing widespread damage to the impacted tissue. Various parameters of the shape and materials used in these projectiles control the level of destruction within the target. While these projectiles potentially lead to an increased risk of harm to other than the intended target due to their increased range, measures have been taken to limit the ability for the projectile to pass through the target.
U.S. Pat. No. 4,776,279 discloses a projectile of that has a smooth aerodynamic shape with a soft tip and core, where the projectile body has slits in the exterior to cause the projectile body to expand in a controlled manner upon impact. U.S. Pat. No. 4,136,616, discloses a hollow projectile that rapidly deforms on impact and increases in surface area causing widespread destruction and limiting the likelihood of the projectile passing through the target. U.S. Pat. No. 4,665,827 discloses a projectile that has a screw inserted in the tip that upon impact causes the arms of the projectile to fan out and cause increased destruction.
A different approach to projectile design has focussed on the addition of range limiting features to projectiles to reduce the likelihood of severe harm to those beyond the effective range of the bullet. These bullets still provide a high level of lethality while reducing the overall range of the projectile body. Projectiles of this type expand upon firing or while in-flight, where the increased surface area slows the projectile, thereby limiting the range of the projectile. U.S. Pat. No. 4,006,667 discloses one example of a projectile that upon firing, changes shape causing a plurality of arms to deploy from the sides of the projectile body. The spin of the projectile as it exits the firearm causes a centrifugal force to separate the arms from the projectile body. The increased surface area of the arms cause the projectile to slow down.
Bullets that increase in size or alter their own shape in-flight are additionally used by police for crowd control applications where lethality and penetration of the projectile is not desired. These projectiles are made to deform rapidly and may modify their shape based on centrifugal forces imparted by the rifling of the barrel. U.S. Pat. No. 5,450,795 discloses one type of projectile where a gel filled sack is surrounded by a fabric cover. Upon firing the cover acts to slow the projectile (sack), and upon impact the sack may rupture further distributing the load. U.S. Pat. No. 3,952,662 is another projectile that has arms that extend from the side of the projectile body upon firing, where the arms slow the projectile and additionally help to distribute load transferred to the impacted region of the target.
What is desired therefore is a projectile modification where the projectile body may be of any type desired by the user, where the modified projectile has a very low potential to pass through the target. The modification should be simple to add to a projectile body and should provide an additional braking force once the projectile has sufficiently entered the target. While prior art projectiles may use mechanical or aerodynamic or impact force means to modify the shape of the projectile, none offer the ability to externally modify a prior art bullet where arms spring out radially to extend the reach of the projectile immediately upon firing. Upon impact the projectile passes into the target according to the design properties of the particular projectile modified, then hook-like projections on the extended arms engage the surface to pull and tear the surface and internal tissue thereby increasing damage and reducing the potential for the projectile to passthrough the target.